1. Field of Invention
The present invention relates to digital printing apparatus and methods, and more particularly to a method and an apparatus for holding and winding of a film of lithographic printing material for digital printing press or plate imager equipment.
2. Description of Background Art
A plate-material supply spool (PMSS) has a predetermined amount of plate material film wrapped as a roll around a core. The core of current plate-material supply spool is formed of a heavy-duty, dimensionally stable material, such as stainless steel.
During the operation of a printing press or a plate imager equipment the plate material is transferred from the supply spool to an uptake spool. After exposing the entire film of the plate material, the core of the empty supply spool and the full uptake spool are removed. The core of the empty supply spool is installed as a new empty uptake spool. The full uptake spool can be disposed. More information on the current PMSS and printing machine can be found in U.S. Pat. No. 5,727,749 and U.S. design Pat. 372,118, the entire contents of which are incorporated herein by reference.
Following are some limitations of the current supply spool. The plate material supply spool is quite expensive due to the cost of the heavy-duty core that is embedded within each one of the plate material supply spool. Furthermore, the plate material supply spool is quite heavy due to the weight of its core, which increases the transportation cost. Last but not the least, handling and/or recycling the used plate material spool having the heavy-duty core is complicated.
Therefore, it is evident that there is a need for an apparatus and a method for assembling the spool of plate material. The new method and apparatus will reduce the cost of a plate material supply spool (PMSS), reduce the cost of transportation and the cost of recycling and or disposing of the used full uptake spool including plate material.